Pulse oximetry is now commonly employed along with non-invasive blood pressure, respiratory rate, and temperature in multi-parameter vital signs monitors. Such monitors are carried by hospital nursing staff from room to room for carrying out routine vital signs checks from four to six times per day. It is common practice for the nursing staff to carry a notebook and record manually various vital signs adjacent to the patient""s name.
Since hospital patients invariably wear a wrist bracelet for identification, it would be most convenient to use the wristband to automatically record the patient""s name and identification number each time that vital signs are taken. Wristbands with bar codes are not in common use at this time for patient identification, but interest is growing in the use of bar codes for this purpose. Since the pulse oximeter is invariably placed on a patient""s finger to obtain oxygen saturation, it would be advantageous to use the same motion to cause the pulse oximeter probe to be used as a bar code reader.
The present invention provides an apparatus and method for simultaneously determining the patient""s identification and blood oxygen saturation. The invention utilizes prior art pulse oximeters and prior art bar coded wristbands, for example. These individual prior art items have not heretofore been utilized together to automatically obtain and record the patient""s identification together with blood oxygen saturation.
Reading the bar code on the wristband is accomplished by placing a combination emitter/detector in the distal end of the oximeter probe. Since the emitter/detector must pass directly over the bar code, this arrangement requires that the end of the pulse oximeter probe make direct contact with the patient""s wristband. No deviation from the wristband is permitted when a simple LED bar coder is employed.
An alternative optical method, using a laser diode or a combination of laser diodes and detectors, enables the user to hold the bar code reader a few inches from the coded strip. The electronics for interpreting the reflected light is somewhat more complicated than with the simpler LED system, and the cost of the laser diodes and the complexity of the electronics makes this alternative method somewhat more costly to manufacture than simply employing an LED and a photodetector at the end of the pulse oximeter probe.